as for the ballistics, oo magbabago, pero sa totoo lang, i don't know of any local case being solved by comparing rifling marks. at least not yet. i don't even think all the FED records are in a computer searchable database.

I know someone who bought an aftermarket barrel and took the barrel to FED to have it registered. When FED saw the barrel, they have no idea how to register it since there is no serial number on the barrel. So they told the guy, "sige gamitin mo na, hindi mo naman siguro gagamitin sa masama yan eh."

When you buy a frame, it must be licensed/registered at FED...but if you buy a barrel, the more it must be licensed/registered and "fingerprinted" for its' barrel rifling. You can alter frame serial numbers but not rifling marks. If FED does not do this, how in the world are they going to present recovered bullets and shells as evidence during trials that this came from this gun registered to this person etc...well if it's a loose "barrel" that is another story...that's why there is amnesty...Buy a licensed 1911; change the barrel, firing pin, extractor and what have you? An untraceable loose firearm, imo